Cyclopentanone derivative

ABSTRACT

A novel cyclopentanone derivative having a cyclopentanone or cyclopentanol ring having substituents at the 2- and 5-positions is provided. The cyclopentanone derivative preferably has 13 to 17 carbon atoms. A perfume composition comprising the cyclopentanone derivative emits a flora fragrance emphasizing a natural and fresh feeling. It is useful for perfuming a variety of toiletries and households. A process for preparing the above-mentioned cyclopentanone derivative is also provided by which the cyclopentanone derivative can be obtained in a practically acceptable yield.

TECHNICAL FIELD

This invention relates to a cyclopentanone derivative and a perfumecomposition comprising the same, which are used for a perfume, a soap, ashampoo, a hair rinse, a body shampoo, a detergent, a cosmetic, a hairspray, an aromatic, and others.

BACKGROUND ART

It is known that cyclopentanone derivatives include those which areuseful as a perfume. As specific examples of the cyclopentanonederivatives used as a perfume, there can be mentioned methyl2-(cis-2-pentenyl)-3-oxocyclopent-3-yl-acetate (trivial name: methyljasmonate) and methyl 2-n-pentenyl-3-oxocyclopent-3-yl-acetate (trivialname: methyl dihydrojasmonate), which are known as a perfume emitting ajasmin-like floral scent; and 2-cyclopentyl cyclopentylorotonate whichis known as a perfume emitting a fruity and juicy scent.

A cyclopentanone derivative represented by the following general formula(A):

wherein R^(L) represents an alkyl group having 4 to 6 carbon atoms, anda fragrance-emitting or flavor-giving preparation comprising thecyclopentanone derivative have been proposed in Japanese UnexaminedPatent Publication No. S52-139046. It is described in this publicationthat this cyclopentanone derivative emits a fruity and freshapricot-like fragrance,

User's or consumer's fancy for fragrance-emitting preparations andproducts varies depending upon the particular age and sex distinction.The kinds of such products and the purposes of use thereof are beingrapidly expanded, and therefore, various fragrance-emitting or modifyingingredients giving products emitting fragrant scents, which aredelicately different in primary tone, depth, amplitude and volume, aredesired.

A perfume ingredient is a kind of physiologically active substance. Itis known that modification of its chemical structure delicatelyinfluences and occasionally greatly changes the fragrance of theingredient, perceived by a human being. Therefore it is important fordeveloping a novel perfume compound to synthesize analogues andderivatives of a known perfume compound and assess the fragrancethereof.

DISCLOSURE OF THE INVENTION

An object of the present invention is to provide a oyclopentanonederivative useful as a novel perfume ingredient emitting a floralfragrance, and to provide a perfume composition comprising thecyclopentanone derivative.

To achieve the above-mentioned object, the present inventors synthesizedvarious cyclopentanone derivatives having substituents at 2- and5-positions of a cyclopentanone or cyclopentanol structure, and assessedtheir fragrances and perfume compositions comprising the same.Consequently, the present inventors have found that specificcyclopentanone derivatives emit a floral fragrance, and that perfumecompositions comprising the cyclopentanone derivatives diffuse a floralfragrance and are useful for giving a natural and fresh scent to varietyof toiletries. Based on these findings, the present invention has beencompleted.

Another object of the present invention is to provide a process forpreparing the above-mentioned cyclopentanone derivatives in apractically acceptable yield.

Thus, in accordance with the present invention, there are provided thefollowing cyclopentanone derivatives and perfume compositions.

(i) A cyclopentanone derivative represented by the following generalformula (1):

wherein R¹ represents an alkyl group having 4 to 7 carbon atoms, analkylidene group having 4 to 7 carbon atoms, a cyclohexyl group or acyclohexylidene group, R² represents an alkyl group having 4 to 7 carbonatoms, an alkylidene group having 4 to 7 carbon atoms, a cyclopentylgroup, a cyclopentylidene group, a cyclohexyl group or a cyclohexylidenegroup, R³ and R⁴ independently represent a hydrogen atom or an alkylgroup having 1 to 4 carbon atoms, and —Y represents —OH or ═O.

(ii) A cyclopentanone derivative represented by the following generalformula (2):

wherein R⁵ represents an alkyl group having 4 or 5 carbon atoms or analkylidene group having 4 or 5 carbon atoms, R⁶ represents an alkylgroup having 4 or 5 carbon atoms, an alkylidene group having 4 or 5carbon atoms, a cyclopentyl group or a cyclopentylidene group, and R³,R⁴ and —Y are the same as defined above.

(iii) A cyclopentanone derivative represented by the following generalformula (3):

wherein R⁷ represents an alkyl group having 5 carbon atoms, or analkylidene group having 5 carbon atoms, R⁸ represents an alkyl grouphaving 5 carbon atoms, an alkylidene group having 5 carbon atoms, acyclopentyl group, or a cyclopentylidene group, and R³, R⁴ and —Y arethe same as defined above.

(iv) The cyclopentanone derivative according to any one of the aboveparagraphs (i) to (iii), which has 13 to 17 carbon atoms in total.

(v) The cyclopentanone derivative according to any one of the aboveparagraphs (i) to (iv), wherein both of R³ and R⁴ are hydrogen atoms.

(vi) A perfume composition comprising at least one cyclopentanonederivative selected from those which are described in the aboveparagraphs (i) to (v).

(vii) A perfume composition comprising 0.1 to 90% by weight of acyclopentanone derivative selected from those which are described in theabove paragraphs (i) to (v).

(viii) In accordance with the present invention, there is furtherprovided a process for preparing a cyclopentanone derivative representedby the following general formula (6):

wherein R¹, R³ and R⁴ are the same as defined above, and R¹¹ representsan alkylidene group having 4 to 7 carbon atoms, a cyclopentylidene groupor a cyclohexylidene group,

-   -   characterized in that a cyclopentanone derivative represented by        the following general formula (4):        wherein R¹, R³ and R⁴ are the same as defined above, is reacted        under alkaline conditions with a ketone or aldehyde represented        by the following general formula (5):        wherein R⁹ and R¹⁰ represents a hydrogen atom, or an alkyl group        having 1 to 6 carbon atoms; the alkyl groups for R⁹ and R¹⁰ may        be bonded together to form a ring; and the total number of        carbon atoms in the sum of the alkyl groups for R⁹ and R¹⁰ is in        the range of 3 to 6.

(ix) In accordance with the present invention, there is further provideda process for preparing a cyclopentanone derivative represented by thefollowing general formula (7):

wherein R³ and R⁴ are the same as defined above, R¹ represents an alkylgroup having 4 to 7 carbon atoms or a cyclohexyl group, and R¹³represents an alkyl group having 4 to 7 carbon atoms, a cyclopentylgroup or a cyclohexyl group,

-   -   characterized in that a cyclopentanone derivative represented by        the above-mentioned general formula (6) is reduced with        hydrogen.

(x) In accordance with the present invention, there is further provideda process for preparing a cyclopentanone derivative represented by thefollowing general formula (8):

wherein R³, R⁴, R¹² and R¹³ are the same as defined above,

-   -   characterized in that a cyclopentanone derivative represented by        the above-mentioned general formula (7) is reduced with        hydrogen.

(xi) In accordance with the present invention, there is further provideda process for preparing a cyclopentanone derivative represented by theabove-mentioned general formula (8),

-   -   characterized in that a cyclopentanone derivative represented by        the following general formula (9):        wherein R³ and R⁴ are the same as defined above, R¹⁴ represents        an alkyl group having 4 to 7 carbon atoms, an alkylidene group        having 4 to 7 carbon atoms, a cyclohexyl group or a        cyclohexylidene group, R¹⁵ represents an alkyl group having 4 to        7 carbon atoms, an alkylidene group having 4 to 7 carbon atoms,        a cyclopentyl group, a cyclopentylidene group, a cyclohexyl        group or a cyclohexylidene group, and at least one of R¹⁴ and        R¹⁵ is the alkylidene group, a cyclohexylidene group or a        cyclopentylidene group, is reduced with hydrogen.

BEST MODE FOR CARRYING OUT THE INVENTION

The invention will now be described in detail with respect tocyclopentanone derivatives, processes for preparing the cyclopentanonederivatives and perfume compositions.

(1) Cyclopentanone Deivatives

The present invention is concerned with cyclopentanone derivativesrepresented by the above-mentioned general formula (1).

In the general formula (1), R¹ includes, for example, chain alkyl groupshaving 4 to 7 carbon atoms, such as n-butyl group, isobutyl group,s-butyl group, t-butyl group, n-pentyl group, neopentyl group, isopentylgroup, t-pentyl group, n-hexyl group, isohexyl group and n-heptyl group;chain alkylidene groups having 4 to 7 carbon atoms, such as n-butylidenegroup, isobutylidene group, n-pentylidene group, neopentylidene group,isopentylidene group, n-hexylidene group, isohexylidene group andn-heptylidene group; and a cyclohexyl group and a cyclohexylidene group.

R² includes, for example, chain alkyl groups having 4 to 7 carbon atoms,such as n-butyl group, isobutyl group, s-butyl group, t-butyl group,n-pentyl group, neopentyl group, isopentyl group, t-pentyl group,n-hexyl group, isohexyl group and n-heptyl group; chain alkylidenegroups having 4 to 7 carbon atoms, such as n-butylidene group,isobutylidene group, n-pentylidene group, neopentylidene group,isopentylidene group, n-hexylidene group, isohexylidene group andn-heptylidene group; and a cyclopentyl group, cyclopentylidene group, acyclohexyl group and a cyclohexylidene group.

R³ and R⁴ independently represent a hydrogen atom, or an alkyl grouphaving 1 to 4 carbon atoms, which include, for example, methyl, ethyl,n-propyl, isopropyl and n-butyl groups.

-   -   —Y represents —OH or ═O.

The cyclopentanone derivative represented by the general formula (1)preferably has 13 to 17 carbon atoms in total. As specific examplesthereof, there can be mentioned the following cyclopentanonederivatives.

(1-1) Cyclopentanone derivatives wherein —Y is ═O2,5-di-n-butylidenecyclopentanone, 2,5-diisobutylidene-cyclopentanone,2,5-di-n-pentylidenecyclopentanone, 2,5-dineopentylidenecyclopentanone,2,5-diisopentylidene-cyclopentanone, 2,5-di-n-hexylidenecyclopentanone,2,5-diisohexylidenecyclopentanone, 2,5-dicyclohexylidene-cyclopentanone,2-n-butylidene-5-isobutylidenecyclopentanone,2-n-butylidene-5-n-pentylidenecyclopentanone,2-n-butylidene-5-neopentylidenecyclopentanone,2-n-butylidene-5-isopentylidenecyclopentanone,2-n-butylidene-5-n-hexylidenecyclopentanone,2-n-butylidene-5-isohexylidene-cyclopentanone,2-n-butylidene-5-n-heptylidene-cyclopentanone,2-n-pentylidene-5-isobutylidenecyclopentanone,2-n-pentylidene-5-neopentylidenecyclopentanone,2-n-pentylidene-5-isopentylidenecyclopentanone,2-n-pentylidene-5-n-hexylidenecyclopentanone,2-n-pentylidene-5-isohexylidenecyclopentanone,2-n-pentylidene-5-n-heptylidene-cyclopentanone,2-n-hexylidene-5-isobutylidenecyclopentanone,2-n-hexylidene-5-neopentylidenecyclopentanone,2-n-hexylidene-5-isopentylidenecyclopentanone,2-n-hexylidene-5-isohexylidene-cyclopentanone,2-cyclopentylidene-5-n-butylideneoyclopentanone,2-cyclopentylidene-5-isobutylidenecyclopentanone,2-cyclopentylidene-5-n-pentylidenecyclopentanone,2-cyclopentylidene-5-neopentylidenecyclopentanone,2-cyclopentylidene-5-isopentylidenecyclopentanone,2-cyclopentylidene-5-n-hexylidenecyclopentanone,2-cyclopentylidene-5-isohexylidenecyclopentanone,2-cyclopentylidene-5-n-heptylidenecyclopentanone,2-cyclopentylidene-5-cyclohexylidenecyclopentanone,2-cyclohexylidene-5-n-butylidenecyclopentanone,2-cyclohexylidene-5-isobutylidenecyclopentanone,2-cyclohexylidene-5-n-pentylidenecyclopentanone,2-cyclohexylidene-5-neopentylidenecyclopentanone,2-cyclohexylidene-5-n-hexylidenecyclopentanone,2-cyclohexylidene-5-isohexylidenecyclopentanone,2-n-pentyl-5-n-butylidenecyclopentanone,2-n-pentyl-5-n-pentylidenecyclopentanone,2-n-pentyl-5-n-hexylidene-cyclopentanone,2-n-pentyl-5-cyclopentylidenecyclopentanone,2-n-pentyl-5-cyclohexylidenecyclopentanone,2-cyclopentyl-5-n-butylidenecyclopentanone,2-cyclopentyl-5-n-pentylidene-cyclopentanone,2-cyclopentyl-5-n-hexylidenecyclopentanone,2-cyclopentyl-5-cyclohexylidenecyclopentanone,2,5-di-n-butyl-cyclopentanone, 2,5-diisobutylcyclopentanone,2,5-di-s-butyl-cyclopentanone, 2,5-di-n-pentylcyclopentanone,2,5-dineopentyl-cyclopentanone, 2,5-di-t-pentylcyclopentanone,2,5-di-n-hexyl-cyclopentanone, 2,5-diisohexylcyclopentanone,2,5-dicyclohexyl-cyclopentanone, 2-n-butyl-5-isobutylcyclopentanone,2-n-butyl-5-n-pentylcyclopentanone, 2-n-butyl-5-neopentylcyclopentanone,2-n-butyl-5-t-pentylcyclopentanone, 2-n-butyl-5-n-hexyl-cyclopentanone,2-n-butyl-5-isohexylcyclopentanone, 2-n-butyl-5-n-heptylcyclopentanone,2-n-pentyl-5-isobutylcyclopentanone, 2-n-pentyl-5-s-butylcyclopentanone,2-n-pentyl-5-neopentyl-cyclopentanone,2-n-pentyl-5-n-hexylcyclopentanone, 2-n-pentyl-5-isohexylcyclopentanone,2-n-pentyl-5-n-heptylcyclopentanone, 2-n-hexyl-5-isobutylcyclopentanone,2-n-hexyl-5-s-butyl-cyclopentanone, 2-n-hexyl-5-neopentylcyclopentanone,2-n-hexyl-5-isopentylclopentanone, 2-n-hexyl-5-t-pentylcyclopentanone,2-n-hexyl-5-isohexylcyclopentanone,2-cyclopentyl-5-n-butyl-cyclopentanone,2-cyclopentyl-5-s-butylcyclopentanone,2-cyclopentyl-5-isobutylcyclopentanone,2-cyclopentyl-5-n-pentylcyclopentanone,2-cyclopentyl-5-neopentyl-cyclopentanone,2-cyclopentyl-5-isopentylcyclopentanone,2-cyclopentyl-5-t-pentylcyclopentanone,2-cyclopentyl-5-n-hexylcyclopentanone,2-cyclopentyl-5-isohexylcyclopentanone,2-cyclopentyl-5-n-heptylcyclopentanone,2-cyclohexyl-5-n-butylcyclopentanone,2-cyclohexyl-5-s-butylcyclopentanone,2-cyclohexyl-5-isobutylcyclopentanone,2-cyclohexyl-5-n-pentylcyclopentanone,2-cyclohexyl-5-neopentyl-cyclopentanone,2-cyclohexyl-5-t-pentylcyclopentanone,2-cyclohexyl-5-n-hexylcyclopentanone,2-cyclohexyl-5-isohexyl-cyclopentanone and2-cyclohexyl-5-cyclopentylcyclopentanone.

(1-2) Cyclopentanone derivatives wherein —Y is —OH2,5-di-n-butylidenecyclopentanol, 2,5-diisobutylidene-cyclopentanol,2,5-di-n-pentylidenecyclopentanol, 2,5-dtneopentylidenecyclopentanol,2,5-diisopentylidene-cyclopentanol, 2,5-di-n-hexylidenecyclopentanol,2,5-diisohexylidenecyclopentanol, 2,5-dicyclohexylidene-cyclopentanol,2-n-butylidene-5-isobutylidenecyclopentanol,2-n-butylidene-5-n-pentylidenecyclopentanol,2-n-butylidene-5-neopentylidenecyclopentanol,2-n-butylidene-5-isopentylidene-cyclopentanol,2-n-butylidene-5-n-hexylidenecyclopentanol,2-n-butylidene-5-isohexylidenecyclopentanol,2-n-butylidene-5-n-heptylidenecyclopentanol,2-n-pentylidene-5-isobutylidene-cyclopentanol,2-n-pentylidene-5-neopentylidenecyclopentanol,2-n-pentylidene-5-isopentylidenecyclopentanol,2-n-pentylidene-5-n-hexylidenecyclopentanol,2-n-pentylidene-5-isohexylidenecyclopentanol,2-n-pentylidene-5-n-heptylidene-cyclopentanol,2-n-hexylidene-5-isobutylidenecyclopentanol,2-n-hexylidene-5-neopentylidenecyclopentanol,2-n-hexylidene-5-isopentylidenecyclopentanol,2-n-hexylidene-5-isohexylidene-cyclopentanol,2-cyclopentylidene-5-n-butylidenecyclopentanol,2-cyclopentylidene-5-isobutylidenecyclopentanol,2-cyclopentylidene-5-n-pentylidenecyclopentanol,2-cyclopentylidene-5-neopentylidenecyclopentanol,2-cyclopentylidene-5-isopentylidenecyclopentanol,2-cyclopentylidene-5-n-hexylidenecyclopentanol,2-cyclopentylidene-5-isohexylidenecyclopentanol,2-cyclopentylidene-5-n-heptylidenecyclopentanol,2-cyclopentylidene-5-cyclohexylidenecyclopentanol,2-cyclohexylidene-5-n-butylidenecyclopentanol,2-cyclohexylidene-5-isobutylidenecyclopentanol,2-cyclohexylidene-5-n-pentylidenecyclopentanol,2-cyclohexylidene-5-neopentylidenecyclopentanol,2-cyclohexylidene-5-isopentylidenecyclopentanol,2-cyclohexylidene-5-n-hexylidenecyclopentanol,2-cyclohexylidene-5-isohexylidenecyclopentanol,2-n-pentyl-5-n-butylidenecyclopentanol,2-n-pentyl-5-n-pentylidenecyclopentanol,2-n-pentyl-5-n-hexylidene-cyclopentanol,2-n-pentyl-5-cyclopentylidenecyclopentanol,2-n-pentyl-5-cyclohexylidenecyclopentanol,2-cyclopentyl-5-n-butylidenecyclopentanol,2-cyclopentyl-5-n-pentylidene-cyclopentanol,2-cyclopentyl-5-n-hexylidenecyclopentanol,2-cyclopentyl-5-cyclohexylidenecyclopentanol,2,5-di-n-butyl-cyclopentanol, 2,5-diisobutylcyclopentanol,2,5-di-s-butyl-cyclopentanol, 2,5-di-n-pentylcyclopentanol,2,5-dineopentyl-cyclopentanol, 2,5-diisopentylcyclopentanol,2,5-di-t-pentyl-cyclopentanol, 2,5-di-n-hexylcyclopentanol,2,5-diisohexyl-cyclopentanol, 2,5-dicyclohexylcyclopentanol,2-n-butyl-5-isobutylcyclopentanol, 2-n-butyl-5-s-butylcyclopentanol,2-n-butyl-5-n-pentylcyclopentanol, 2-n-butyl-5-neopentyl-cyclopentanol,2-n-butyl-5-isopentylcyclopentanol, 2-n-butyl-5-n-hexylcyclopentanol,2-n-butyl-5-isohexylcyclopentanol, 2-n-butyl-5-n-heptylcyclopentanol,2-n-pentyl-5-isobutyl-cyclopentanol, 2-n-pentyl-5-s-butylcyclopentanol,2-n-pentyl-5-neopentylcyclopentanol,2-n-pentyl-5-isopentylcyclopentanol, 2-n-pentyl-5-t-pentylcyclopentanol,2-n-pentyl-5-n-hexyl-cyclopentanol, 2-n-pentyl-5-isohexylcyclopentanol,2-n-pentyl-5-n-haptylcyclopentanol, 2-n-hexyl-5-isobutylcyclopentanol,2-n-hexyl-5-s-butylcyclopentanol, 2-n-hexyl-5-neopentyl-cyclopentanol,2-n-hexyl-5-isopentylcyclopentanol, 2-n-hexyl-5-t-pentylcyclopentanol,2-n-hexyl-5-isohexylcyclopentanol, 2-cyclopentyl-5-n-butylcyclopentanol,2-cyclopentyl-5-8s-butyl-cyclopentanol,2-cyclopentyl-5-isobutylcyclopentanol,2-cyclopentyl-5-n-pentylcyclopentanol,2-cyclopentyl-5-neopentylcyclopentanol,2-cyclopentyl-5-isopentyl-cyclopentanol,2-cyclopentyl-5-t-pentylcyclopentanol,2-cyclopentyl-5-n-hexylcyclopentanol,2-cyclopentyl-5-isohexylcyclopentanol,2-cyclopentyl-5-n-heptylidene-cyclopentanol,2-cyclohexyl-5-n-butylcyclopentanol,2-cyclohexyl-5-s-butylcyclopentanol,2-cyclohexyl-5-isobutyl-cyclopentanol,2-cyclohexyl-5-n-pentylcyclopentanol,2-cyclohexyl-5-neopentylcyclopentanol,2-cyclohexyl-5-isopentylcyclopentanol,2-cyclohexyl-5-t-pentylcyclopentanol,2-cyclohexyl-5-n-hexylcyclopentanol,2-cyclohexyl-5-isohexyl-cyclopentanol and2-cyclohexyl-5-cyclopentylcyclopentanol.

Among the cyclopentanone derivatives of the present invention, thosewhich represented by the above-mentioned general formula (2) arepreferable. In the general formula (2), R⁵ represents an alkyl grouphaving 4 or 5 carbon atoms or an alkylidene group having 4 or 5 carbonatoms, among the alkyl and alkylidene groups for R¹ in the formula (1).R⁶ represents an alkyl group having 4 or 5 carbon atoms or an alkylidenegroup having 4 or 5 carbon atoms, among the alkyl and alkylidene groupsfor R² in the formula (1), or R⁶ represents a cyclopentyl group or acyclopentylidene group. R³, R⁴ and —Y are the same as defined above.

More preferable cyclopentanone derivatives of the present invention arerepresented by the above-mentioned general formula (3). In the generalformula (3), R⁷ represents an alkyl group having 5 carbon atoms or analkylidene group having 5 carbon atoms, among the alkyl and alkylidenegroups for R¹ in the formula (1). R⁸ represents an alkyl group having 5carbon atoms or an alkylidene group having 5 carbon atoms, among thealkyl and alkylidene groups for R² in the formula (1), or R⁸ representsa cyclopentyl group or a cyclopentylidene group. R³, R⁴ and —Y are thesame as defined above.

In view of ease in synthesis, cyclopentanone derivatives represented bythe general formulae (1), (2) and (3) wherein both of R³ and R⁴ are ahydrogen atom are especially preferable.

(2) Perfume Composition

The present invention is further concerned with a perfume compositioncomprising one kind or more kinds of cyclopentanone derivatives selectedfrom those are represented by the general formulae (1), (2) and (3). Theperfume composition of the present invention can be prepared by mixingtogether predetermined amounts of one kind or more kinds ofcyclopentanone derivatives selected from those are represented by thegeneral formulae (1), (2) and (3), and, if desired, other perfumeingredients and solvent ingredients. The amount of the cyclopentanonederivatives of the general formulae (1), (2) and (3) varies dependingupon the particular kind of perfume ingredients and the particular kindand intense of fragrance, but, it is preferably in the range of 0.1 to90% by weight, more preferably 0.5 to 50% by weight, based on the totalweight of the perfume composition.

As specific examples of other perfume ingredients used, there can bementioned acetyl diisoamylene, acetylcedrene, acetaldehydediethylacetal, anethole, allyl amyl glycolate, allyl heptanoate, allylcaproate, algue absolute, ambrinol, AMBROXAN™, ionone-α, ionone-β,isobornyl acetate, isocamphylcyclohexanol, indole, ethyllinalol,ethylene brassylate, HEDIONE™, eugenol, 11-oxa-16-hexadecanolide,ortho-tert.-butylcyclohexyl acetate, ortho-tert.-butylcyclohexanone,orange oil, chamomile oil, 1-carvone, CALONE™, camphor,gamma-decalactone, caryophyllene, coumarin, CLAIGEON™, clove bud oil,GALAXOLIDE™, geraniol, geranyl acetate, grape fruit oil, geranylnitrile,copaiba balsam, corps pample 10% LIM, diethyl phthalate, citral,1,8-cineol, cyclamen aldehyde, ciste absolute, citronella oil,citronellol, citronellyl formate, dihydro-myroenol, diphenyl oxide,civetone, dimethyl anthranilate, dimethylhydroquinone,dimethylbenzylcarbinol acetate, jasmin oil, JASMOPYRAN™, styralylacetate, spearmint oil, clary sage oil, cedrol, santenal, citronellylacetate, dimethylbenzylcarbinyl acetate, damascenone, thymol,tetrahydromuguol, terpineol, terpinyl acetate, TONALID™, triethylcitrate, tricyclodecenyl acetate, TRIPLAL™, terpineol,trimethylundecenal, neroli oil, neryl acetate, nopil acetate, pine oil,BACDANOL™, basil oil, BASILEX™, PEARLIDE™, mint oil, patchouli oil,α-pinene, phenylethyl alcohol, PHENOXANOL™, bulgeonal, frutate, plenylacetate, hei absolute, cis-3-hexenol, hexyl acetate, β-naphthol ethylether, cis-3-hexenyl salicylate, benzyl acetate, hexylcinnamic aldehyde,hexyl salicylate, cis-3-hexenyl acetate, cis-3-hexenyl salicylate,peppermint oil, helional, heliotropin, bergamot oil, VERTENEX™, benzylacetate, benzyl salicylate, borneol, mayol, methyloctyne carbonate,methyl anthranilate, methyl salicylate, methyl dihydrojasmonate,methylionone, menthone, 1-menthol, eucalyptus oil, lime oil, lavandingrosso, labdanum absolute, lavender oil, limonene, linalool, linalylacetate, LYRAL™, LILIAL™, lemon oil, rose oil, rosemary oil, rosewoodBulgarian and rose Turkish. These perfume ingredients may be used eitheralone or as a combination of at least two thereof.

The amount of these perfume ingredients is usually in the range of 0.1to 500 parts by weight, preferably 1 to 200 parts by weight, per onepart by weight of the cyclopentanone derivative of the presentinvention.

When a carrier is used for impregnation with perfume ingredients, asolvent can be appropriately incorporated in the perfume composition ofthe present invention to enhance the penetration of perfume ingredientsinto the carrier. The solvent used includes, for example, ethanol,polyhydric alcohols, paraffins, glycol ethers and phthalic acid esters.When water is used to enhance the penetration of perfume ingredient intoa carrier, a surface active agent can be added. When the perfumecomposition is used as an aromatic, a fixative can be incorporatedtherein to enhance the preservation of fragrance.

The perfume composition of the present invention diffuses a floralfragrance and is useful for giving a natural and fresh scent to varietyof toiletries and household products, which include, for example, aperfume, a soap, a shampoo, a hair rinse, a body shampoo, a detergent, acosmetics a hair spray and an aromatic.

(3) Process for Preparation of Cyclopentanone Derivatives

Among the cyclopentanone derivatives of the general formulae (1) to (3),2,5-dialkylidenecyclopentanone derivatives (1-1) wherein —Y is ═O and R¹and R² are an alkylidene group can be prepared by a process wherein analdol reaction of a cyclopentanone compound Ra—CO—Rb, and a subsequentdehydration reaction are carried out to give amonoalkylidenecyclopentanone derivative (3-2), and then, aldol reactionof the monoalkylidenecyclopentanone derivative (3-2) with an aldehyde,or ketone represented by the formula: Rc—CO—Rd, and a subsequentdehydration reaction are carried out to give adialkylidenecyclopentanone derivative (1-1) (see the following reactionscheme).

wherein R³ and R⁴ are as defined above, Ra and Rc independentlyrepresents an alkyl group having 1 to 6 carbon atoms, Rb and Rdindependently represent a hydrogen atom or an alkyl group having 1 to 6carbon atoms. Ra and Rb may be bonded together to form a cyclohexanering, and Ra and Rd may be bonded together to form a cyclopentane ringor a cyclohexane ring, provided that the total number of carbon atoms inthe sum of Ra and Rb is 3 to 6 and the total number of carbon atoms inthe sum of Rc and Rd is 3 to 6.

The above-mentioned aldol reactions can be carried out in the presenceof a base in a solvent. The base used includes, for example, metalalkoxides such as sodium methoxide, sodium ethoxide, potassiummethoxide, potassium ethoxide and potassium t-butoxide; and metalhydroxides such as sodium hydroxide and potassium hydroxide. These basesmay be used either alone or as a combination of at least two thereof.

The amount of base is usually in the range of 0.1 to 2 moles, preferably0.5 to 1.5 moles and more preferably 0.8 to 1.2 moles, per mole of thecyclopentanone compound (3-1).

The solvent used is not particularly limited, provided that it is aninert solvent, and, as specific examples thereof, there can be mentionedalcohols such as methanol and ethanol; aliphatic can be mentionedalcohols such as methanol and ethanol; aliphatic hydrocarbons such asn-hexane, n-heptane, n-octane, cyclopentane and cyclohexane; aromatichydrocarbons such as benzene, toluene, ethylbenzene and xylene, andethers such as diethyl ether, dibutyl ether, tetrahydrofuran anddioxane. These solvents may be used either alone or as a combination ofat least two thereof.

The amount of aldehydes or ketones, represented by the formulae Ra—CO—Rband Ro—CO—Rd is usually in the range of 0.1 to 2 moles, preferably 0.5to 1.5 moles and more preferably 0.8 to 1.2 moles, per mole of thecyclopentanone compound (3-1).

The reaction temperature for the aldol reactions is usually in the rangeof 20 to 180° C., preferably 40 to 140° C. and more preferably 60 to100° C. The reaction can be carried out either under subatmosphericpressure or pressure.

The dehydration reactions are carried out by, for example, (i) a methodwherein a reaction liquid containing an aldol reaction product isfurther heated as it is without isolation of the aldol reaction product;(ii) a method wherein a reaction liquid containing an aldol reactionproduct is neutralized, an acid catalyst is added to the neutralizedreaction liquid, and then the reaction liquid is heated; or (iii) amethod wherein an aldol reaction product is isolated from a reactionliquid containing the aldol reaction product, and the isolated reactionproduct is stirred in an appropriate solvent in the presence of an acidcatalyst at a temperature in the range of room temperature to theboiling point of the solvent.

The acid catalyst used In the above-mentioned methods (ii) and (iii)includes, for example, inorganic acids such as hydrochloric acid andsulfuric acid; and organic acids such as paratoluenesulfonic acid,benzenesulfonic acid, methanesulfonic acid, acetic acid and oxalic acid.The amount of acid catalyst is usually in the range of 0.001 to 5 moles,preferably 0.01 to 3 moles, per mole of the aldol reaction product.

Among the cyclopentanone derivatives represented by the general formulae(1), (2) and (3), cyclopentanone derivatives (1-2) in which R¹ and R²are the same alkylidene group, R⁵ and R⁶ are the can be prepared by analdol reaction between one molecule of cyclopentanone compounds (3-1)and two molecules of a compound represented by the formula Ra—CO—Rb, anda subsequent dehydrogenation reaction.

After completion of the dehydration reactions, the reaction products aresubjected to conventional after-treatment and purification such ascolumn chromatography, distillation or recrystallization whereby2,5-dialkylidenecyclopentanone derivatives (1-1) and (1-2) can beisolated.

2,5-dialkylidenecyclopentanol derivative (1-3) can be prepared byreducing the carbonyl group of 2,5-dialkylidenecyclopentanone derivative(1-1) (see the following reaction scheme).

wherein R³, R⁴, Ra, Rb, Ra and Rd are the same as defined above.

2,5-dialkylcyclopentanol derivative (1-4) can be prepared byhydrogenating the carbon-carbon double bond of2,5-dialkylidenecyclopentanone derivative (1-1) (see the followingreaction scheme).

wherein R³, R⁴, Ra, Rb, Re and Rd are the same as defined above.

2,5-dialkylcyclopentanol derivative (1-5) can be prepared byhydrogenating the carbon-carbon double bond of2,5-dialkylidenecyclopentanol derivative (1-3). Alternatively,2,5-dialkylcyclopentanol derivative (1-5) can be prepared by reducingthe carbonyl group of 2,5-dialkylcyclopentanone derivative (1-4) (seethe following reaction scheme).

wherein R³, R⁴, Ra, Rb, Rc and Rd are the same as defined above.

The reducing procedures adopted for the above-mentioned reductionreactions are not particularly limited. In the case where the carbonylgroup is reduced, a reducing agent such as sodium boron hydride (NaBH₄),lithium aluminum hydride (LiAlH₄) or diisobutylaluminum hydride(iBu₂AlH) is preferably used. In the case where the carbon-carbon doublebond is hydrogenated, a catalytic hydrogenation reduction is preferablyadopted using a hydrogenation catalyst such as palladium, ruthenium,rhodium, platinum or Raney nickel catalyst.

After completion of the reaction for obtaining cyclopentanone andcyclopentanol derivatives of the formulae (1-3) to (1-5), when acatalyst has been used for the reducing reaction., the catalyst isfiltered off. When a reducing agent such as NaBH₄ or LiAlH₄ is used.,the reaction liquid is neutralized with, for example, hydrochloric acid,and then, an organic phase is separated from an aqueous phase.Thereafter, the objective compound can be isolated by a conventionalpurifying procedure such as column chromatography, distillation orrecrystallization.

Among the cyclopentanone derivatives of the present invention, a2,5-dialkylcyclopentanone derivative of the formula (1-7) can also beprepared by the process shown in the following reaction scheme.

wherein R³ and R⁴ are as defined above, R^(1a) and R^(a) independentlyrepresent an alkyl group having 4 to 7 carbon atoms, and X¹ and X²independently represent a halogen atom such as chlorine, bromine oriodine.

More specifically 2,5-dialkylcyclopentanone derivative (1-7) can beprepared by a process wherein cyclopentanone compound (3-1) is reactedwith an alkyl halide represented by the formula R^(1a)—X¹ in thepresence of a base in a solvent to give a monoalkylcyclopentanonederivative (1-6), and then, the monoalkylcyclopentanone derivative (1-6)is reacted with an alkyl halide represented by the formula R^(2a)—X² inthe presence of a base in a solvent to give 2,5-dialkylcyclopentanonederivative (1-7).

As specific examples of the base used in the above reaction, there canbe mentioned metal alkoxides such as sodium methoxide, sodium ethoxide,potassium methoxide, potassium ethoxide, potassium t-butoxide andmagnesium ethoxide; metal hydrides such as sodium hydride, potassiumhydride and calcium hydride; and organic bases such as1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and1,4-diazabicyclo[2.2.2]octane (Dabco).

As specific examples of the solvent used in the above reaction, therecan be mentioned aromatic hydrocarbons such as benzene, toluene, xyleneand ethylbenzene; aliphatic hydrocarbons such as n-hexane, n-heptane,n-octane, cyclopentane and cyclohexane; ethers such as diethyl ether,diisopropyl ether, dibutyl ether, tetrahydrofuran, dioxane and1,2-dimethoxyethane; amides such as N,N-diemthylformamide,N,N-dimethylacetamide and N-methylpyrrolidone; and sulfur-containingcompounds such as dimethylsulfoxide and sulfolane.

The amount of alkyl halides represented by the formulae R^(1a)—X¹ andR^(2a)-X², used in the above reactions, is usually in the range of 1 to2 moles per mole of cyclopentanone compound (3-1). The amount of baseused in the above reaction is usually in the range of 1 to 3 moles permole of cyclopentanone compound (3-1). The above-mentioned reactionssmoothly proceed at a temperature in the range of −20° C. to the boilingof the solvent used. After completion of the reactions, the objectivecompound can be isolated by a conventional after-treatment and apurification procedure such as column chromatography, recrystallizationor distillation.

A 2,5-dialkylcyclopentanol derivative of the formula (1-5) can also beprepared by a process wherein an aldol reaction ofmonoalkylcyclopentanone derivative (1-6) with an aldehyde or a ketone,represented by the formula: Rc—CO—Rd, and a subsequent dehydrogenationreaction are carried out to give a 2-alkyl-5-alkylidenecyclopentanonederivative (1-8), and then, the carbon-carbon double bond of thederivative (1-8) is hydrogenated and further the carbonyl group of thederivative (1-8) is reduced (see the following reaction scheme).

wherein R³, R⁴, R^(1a), Rc and Rd are as defined above.

The starting material used in the above reaction, i.e., cyclopentanonecompound (3-1), can be synthesized by a conventional process, forexample, a process wherein cyclopentene is hydrated to givecyclopentanol, and the cyclopentanol is oxidized, or the startingmaterial is commercially available.

Monoalkylcyclopentanone derivative (1-6) used in the above reaction canalso be prepared by hydrogenating the carbon-carbon double bond ofmonoalkylidenecyclopentanone derivative (3-2).

The chemical structures of the above-mentioned compounds can bedetermined by NMR spectrum, IR spectrum, mass spectrum and elementalanalysis.

The cyclopentanone derivatives of the present invention, represented bythe formula (1), have a powdery and floral fragrance.

EXAMPLES

The invention will now be described in more detail by the followingexamples that by no means limit the scope of the invention.

Example 1 Preparation of 2-n-pentyl-5-cyclopentylcyclopentanol

A four-necked three liter flask equipped with a stirrer, a refluxcondenser, a dropping funnel and a thermometer was charged refluxcondenser, a dropping funnel and a thermometer was charged with 482.5 g(2.5 moles) of 28% sodium methoxide (NaOMe) and 1,000 ml ofethylbenzene, and the temperature of the mixture was elevated to 80° C.while being stirred. Thereafter 385.5 g (2.5 moles) of2-n-pentylcyclopentanone was added over a period of 30 minutes, and themixture was further stirred for 30 minutes. Then 210.5 g (2.5 moles) ofcyclopentanone was added over a period of 20 minutes and the mixture wasfurther stirred for 6 hours. To the reaction liquid, 1,000 g (2.75moles) of 10% hydrochloric acid was added to neutralize the reactionliquid. An organic phase was separated from an aqueous phase, and driedover an anhydrous magnesium sulfate, and then filtered. The filtrate wasconcentrated, and the concentrate was purified by silica gel columnchromatography using a mixed liquid of ethyl acetate/n-hexane (1:5) asan elute, to give 154 g of 2-n-pentyl-5-cyclopentylidenecyclopentanone.Yield: 28%.

Thereafter, a three-necked one liter flask equipped with a stirrer, areflux condenser and a thermometer was charged with 154 g (0.7 mole) of2-n-pentyl-5-cyclopentylidenecyclopentanone, 480 g of ethanol and 7.7 gof 5% Pd/C, and then flushed with nitrogen three times and then withhydrogen three times. Then the content was stirred at a temperature of25 to 35° C. and a pressure of 0 to 0.1 MPa for 8 hours. Aftercompletion of reaction, the catalyst was filtered off, and the filtratewas concentrated. Then the concentrate was purified by silica gel columnchromatography using a mixed liquid of ethyl acetate/n-hexane (1:5) asan elute, to give 62.2 g of 2-n-pentyl-5-cyclopentylcyclopentanone witha purity of 99.5%. Yield: 40%.

¹H-NMR spectrum data (CDCl₃, TMS) δppm: 0.88 (and CH₃ of n-pentyl groupat 2-position, 3H), 1.18-1.30, 1.34, 1.51-1.67, 1.75, 1.85, 1.90,2.01-2.12, 2.18 (CH₂ of n-pentyl group at 2-position, CH₂ ofcyclopentanone ring, and CH₂ of cyclopentyl group at 5-position, 20H),1.96, 2.01-2.12 (CH of cyclopentanone ring, and CH of cyclopentyl groupat 5-position, 3H)

Finally, a four-necked 300 ml flask equipped with a stirrer, a refluxcondenser, a dropping funnel and a thermometer was charged with 9.6 g(0.25 mole) of sodium boron hydride and 100 ml of ethanol. Whle thecontent was stirred at a temperature of 30 to 40° C., 55.5 g (0.25 mole)of 2-n-pentyl-5-cyclopentylcyclopentanone was added over a period of 35minutes, and the mixture was further stirred at the same temperature for15 hours. Then the reaction liquid was poured into 380 g (0.4 mole) of4% hydrochloric acid, and the reaction product was extracted with 150 mlof toluene. An organic phase was dried over an anhydrous magnesiumsulfate, and then filtered. The filtrate was concentrated, and theconcentrate was purified by silica gel column chromatography using amixed liquid of ethyl acetate/n-hexane (1:5) as an elute, to give 35.3 gof 2-n-pentyl-5-cyclopentylcyclopentanol with a purity of 99%.

Yield: 63%.

This compound had fruty, and fresh, floral green fragrance.

¹H-NMR spectrum data (CDCl₃, TMS) δppm: 0.84 (end CH₃ of n-pentyl groupat 2-position, 3H), 1.15-1.50 (CH₂ of cyclopentanol ring, CH₂ ofn-pentyl group at 2-position, and CH₂ of cyclopentyl group at5-position, 20H), 1.63-1.90 (CH, 2H), 1.95 (—OH, 1H, this peakdisappeared at treatment with D₂O), 3.85 (CH adjacent to OH group, 1H)

IR spectrum data (KBr): 3200-3550 cm⁻¹ (OH)

Example 2 Preparation of 2-cyclohexyl-5-cyclopentylcyclopentanol

A four-necked one liter flask equipped with a stirrer, a refluxcondenser, a dropping funnel and a thermometer was charged with 96.5 g(0.5 mole) of 28% sodium methoxide and 200 ml of ethylbenzene, and thetemperature of the mixture was elevated to 80° C. while being stirred.The content was further stirred for 30 minutes. Then 76.1 g (0.5 mole)of 2-cyclopentylideneclopentanone was added over a period of 20 minutes,and the mixture was further stirred for 30 minutes. Then 49.1 g (0.5mole) of cyclohexanone was added over a period of 15 minutes and themixture was further stirred for 5 hours. To the reaction liquid, 200 g(0.55 mole) of 10% hydrochloric acid was added to neutralize thereaction liquid. An organic phase was separated, and dried over ananhydrous magnesium sulfate, and then filtered. The filtrate wasconcentrated, and the concentrate was purified by silica gel columnchromatography using a mixed liquid of ethyl acetate/n-hexane (1:5) asan elute, to give 25.7 g of2-cyclohexylidene-5-cyclopentylidenecyclopentanone. Yield: 22%.

Thereafter, a three-necked one liter flask equipped with s stirrer, areflux condenser and a thermometer was charged with 25.7 g (0.11 mole)of 2-cyclohexylidene-5-cyclopentylidene-cyclopentanone, 80 g of ethanoland 1.3 g of 5% Pd/C, and then flushed with nitrogen three times andthen with hydrogen three times. Then the content was stirred at atemperature of 25 to 35° C. and a pressure of 0 to 0.1 MPa for 10 hours.After completion of reaction, the catalyst was filtered off, and thefiltrate was concentrated. Then the concentrate was purified by silicagel column chromatography using a mixed liquid of ethyl acetate/n-hexane(1:5) as an elute, to give 11.7 g of2-cyclohexy-5-cyclopentylcyclopentanone with a purity of 99.3%. Yield:45%.

¹H-NMR spectrum data (CDCl₃, EMS) δppm: 1.0, 1.15-1.28, 1.50-1.71,1.85-1.92, 1.97-2.10 (CH₂ of cyclopentyl group at 2-position, CH₂ ofcyclopentanone ring, and CH₂ of cyclohexyl group at 5-position, 22H),1.97-2.1 (CH of cyclopentyl group at 2-position, CH of cyclopentanonering, and CH of cyclohexyl group at 5-position, 4H)

Finally, a four-necked 300 ml flask equipped with a stirrer, a refluxcondenser, a dropping funnel and a thermometer was charged with 1.9 g(0.05 mole) of sodium boron hydride and 120 ml of ethanol. While thecontent was stirred at a temperature of 30 to 40° C., 11.7 g (0.05 mole)of 2-cyclohexyl-5-cyclopentylcyclopentanone was added over a period of35 minutes, and the mixture was further stirred for 18 hours. Then thereaction liquid was poured into 63 g (0.069 mole) of 4% hydrochloricacid, and the reaction product was extracted with 100 ml of toluene. Anorganic phase was dried over an anhydrous magnesium sulfate, and thenfiltered. The filtrate was concentrated, and the concentrate waspurified by silica gel column chromatography using a mixed liquid ofethyl acetate/n-hexane (1:5) as an elute, to give 6.8 g of2-cycclohexyl-5-cyclopentylcyclopentanol with a purity of 99.2%.

Yield: 58%.

This compound had fresh, vanilla-like, sweat and herbal fragrance.

¹H-NMR spectrum data (CDCl₃, TMS) δppm: 1.02-1.25, 1.33-1.70, 1.80-1.95(CH₂ of cyclopentyl group at 2-position, CH₂ of cyclopentanone ring, andCH₂ of cyclohexyl group at 5-position, 22H), 1.55, 1.87-1.95 (CH ofcyclopentyl group at 2-position, CH of cyclopentanone ring, and CH ofcyclohexyl group at 5-position, 3H), 1.93 (—OH, 1H, this peakdisappeared at treatment with D₂O), 3.90 (CH adjacent to OH group, 1H)

IR spectrum data (KBr): 3200-3550 cm⁻¹ (OH)

Example 3 Preparation of 2,5-di-n-pentylcyclopentanol

A four-necked 500 ml flask equipped with a stirrer, a thermometer, anitrogen seal and a valeroaldehyde-dropping nozzle was charged with138.6 g (0.9 mole) of 2-n-pentylcyclopentanone, 38 g of water and 2.2 gof an aqueous 25% by weight of sodium hydroxide solution. To themixture, 43 g (0.5 mole) of valeroaldehyde was dropwise added at 25° C.over a period of 2.5 hours, and the mixture was further stirred at thesame temperature for 1 hour. To the reaction liquid, 57 g (0.015 mole)of 1% hydrochloric acid was added to neutralize the reaction liquid. Anorganic phase was separated, and dried over an anhydrous magnesiumsulfate, and then filtered. Unreacted raw material was distilled offunder reduced pressure from the filtrate, and the obtained residue waspurified by silica gel column chromatography using a mixed liquid ofethyl acetate/n-hexane (1:5) as an elute, to give 79.0 g of2-(1-hydroxy)pentyl-5-n-pentylcyclopentanone. Yield: 37%.

Thereafter, a three-necked 500 ml flask equipped with 8 stirrer, aDimroth condenser with a Dean-Stark trap, and a thermometer was chargedwith 79.0 g (0.33 mole) of 2-(1-hydroxy)pentyl-5-n-pentylcyclopentanone,130 ml of toluene and 1.5 g (0.012 mole) of oxalic acid dehydrate. Thecontent was refluxed for 3 hours, while water was removed from thecontent by the Dean-Stark trap. The reaction liquid was neutralized with50 g of an aqueous 5% sodium bicarbonate solution. An organic phase wasseparated, and washed with water. Then, the washed organic phase wasdried over anhydrous magnesium sulfate, and then filtered. The filtratewas concentrated, and then the concentrate was purified by silica gelcolumn chromatography using a mixed liquid of ethyl acetate/n-hexane(1:5) as an elute, to give 31.5 g of2-n-pentylidene-5-n-pentylcyclopentanone. Yield: 43%.

Thereafter, a three-necked 500 ml flask equipped with s stirrer, areflux condenser and a thermometer was charged with 31.5 g (0.14 mole)of 2-n-pentylidene-5-n-pentylcyclopentanone, 100 g of ethanol and 1.6 gof 5% Pd/C, and then the content was flushed with nitrogen three timesand then with hydrogen three times. Then the content was stirred at atemperature of 25 to 3° C. and a pressure of 0 to 0.1 MPa for 7 hours.After completion of reaction, the catalyst was filtered off, and thefiltrate was concentrated under reduced pressure. Then the concentratewas purified by silica gel column chromatography using a mixed liquid ofethyl acetate/n-hexane (1:5) as an elute, to give 14.9 g of2,5-di-n-pentylcyclopentanone with a purity of 99.4%. Yield: 47%.

¹H-NMR spectrum data (CDCl₃, TMS) δppm: 0.88 (end CH₃ of cyclopentylgroups at 2- and 5-positions, 6H), 1.30, 1.60, 1.80, 2.20 (CH₂ ofcyclopentyl groups at 2- and 5-positions, and CH₂ of cyclopentanonering, 20H), 2.0 (CH of cyclopentanone ring, 2H)

Finally, a four-necked 300 ml flask equipped with a stirrer, a refluxcondenser, a dropping funnel and a thermometer was charged with 2.5 g(0.066 mole) of sodium boron hydride and 120 ml of ethanol. While thecontent was stirred at a temperature of 30 to 40° C., 14.9 g (0.066mole) of 2,5-di-n-pentylcyclopentanone was added over a period of 35minutes, and the mixture was further stirred for 16 hours. Then thereaction liquid was poured into 84 g (0.092 mole) of 4% hydrochloricacid, and the reaction product was extracted with 100 ml of toluene. Anorganic phase was dried over an anhydrous magnesium sulfate, and thenfiltered. The filtrate was concentrated, and the ooncentrate waspurified by silica gel column chromatography using a mixed liquid ofethyl acetate/n-hexane (1:5) as an elute, to give 9.0 g of2,5-di-n-pentylcyclopentanol with a purity of 99.2%. Yield: 60%.

This compound had fresh, herbal-spicy and green fragrance.

¹H-NMR spectrum data (CDCl₃, TMS) δppm: 0.85 (end CH₃ of cyclopentylgroups at 2- and 5-positions, 6H), 1.2, 1.33, 1.76, 1.90 (CH₂ ofcyclopentyl groups at 2- and 5-positions, and CH₂ of cyclopentanonering, 20H), 1.7 (CH of cyclopentanone ring, 2H), 1.98 (—OH, 1H, thispeak disappeared at treatment with D₂O), 3.75 (CH adjacent to OH group,1H)

IR spectrum data (KBr): 3200-3550 cm⁻¹ (OH)

Example 4 Preparation of Perfume Composition

2-n-pentyl-5-cyclopentylcyclopentanol prepared in Example 1 was mixedtogether with other perfume ingredients in amounts shown in Table 1 toprepare a perfume composition.

An organoleptic test of the perfume composition was carried out by sevenpanelists A, B, C, D, E, F and G. The test results are shown in Table 2.TABLE 1 Perfume ingredients Amounts (parts by weight)2-n-pentyl-5-cyclopentylcyclopentan-l-ol 10 Linalyl acetate 2 Helional 2Styralyl aceate 4 Methyl anthranilate 4 Dihydromyrcenol 10 Cis-3-hexenylsalicylate 70 Dimethylbenzylcarbinyl acetate 10 Terpineol 10 Benzylacetate 30 LILIAL ™ (Givaudin) 40 Phenylethyl alcohol 50 LYRAL ™ (IFF)140 CLAIGEON ™ (Zeon Corporation) 150 Eugenol 10 Methyl ionon 30Isocamphylcyclohexanol 30 Acetyl cedrene 40 GALAXOLIDE ™ (IFF) 60Diethyl phthalate 258 TONALID ™ (PFW) 40 Total 1,000

Note, Name within parenthesis represents a manufacturing company. TABLE2 Panelist Evaluation results A Calm and exalted green fragrance B Greenand sweet, and nobly and distinguishably dressed fragrance C Elegantfloral, herbal and green fragrance D Mint gum-like fragrance E Exaltedsweet and distinguishable fragrance F Jasmin-like sweet fragrance GTotally well balanced fragrance, and exalted floral green top-note

INDUSTRIAL APPLICABILITY

In accordance with the present invention, cyclopentanone derivativesuseful as perfume ingredients having powdery and floral fragrance areprovided. A perfume composition comprising the cyclopentanone derivativeof the present invention emitting floral fragrance which is natural andfresh, and is useful for perfuming a variety of toiletries andhouseholds. In accordance with the present invention, a process forpreparing the above-mentioned cyclopentanone derivatives is furtherprovided by which the objective compounds can be obtained in apractically acceptable yield.

1. A cyclopentanone derivative represented by the following generalformula (1):

wherein R¹ represents an alkyl group having 4 to 7 carbon atoms, analkylidene group having 4 to 7 carbon atoms a cyclohexyl group or acyclohexylidene group, R² represents an alkyl group having 4 to 7 carbonatoms, an alkylidene group having 4 to 7 carbon atoms, a cyclopentylgroup, a cyclopentylidene group, a cyclohexyl group or a cyclohexylidenegroup, R³ and R⁴ independently represent a hydrogen atom or an alkylgroup having 1 to 4 carbon atoms, and −Y represents —OH or ═O.
 2. Acyclopentanone derivative represented by the following general formula(2):

wherein R⁵ represents an alkyl group having 4 or 5 carbon atoms or analkylidene group having 4 or 5 carbon atoms, R⁶ represents an alkylgroup having 4 or 5 carbon atoms, an alkylidene group having 4 or 5carbon atoms, a cyclopentyl group or a cyclopentylidene group, and R³,R⁴ and —Y are the same as defined above.
 3. A cyclopentanone derivativerepresented by the following general formula (3):

wherein R⁷ represents an alkyl group having 5 carbon atoms, or analkylidene group having 5 carbon atoms, R⁸ represents an alkyl grouphaving 5 carbon atoms, an alkylidene group having 5 carbon atoms, acyclopentyl group, or a cyclopentylidene group, and R³, R⁴ and —Y arethe same as defined above.
 4. The cyclopentanone derivative according toany one of claims 1 to 3, which has 13 to 17 carbon atoms in total. 5.The cyclopentanone derivative according to any one of claims 1 to 4,wherein both of R³ and R⁴ are hydrogen atoms.
 6. A perfume compositioncomprising at least one cyclopentanone derivative selected from thosewhich are described in claims 1 to
 5. 7. A perfume compositioncomprising 0.1 to 90% by weight of a cyclopentanone derivative selectedfrom those which are described in claims 1 to
 5. 8. A process forpreparing a cyclopentanone derivative represented by the followinggeneral formula (6):

wherein R¹, R³ and R⁴ are the same as defined above, and R¹¹ representsan alkylidene group having 4 to 7 carbon atoms, a cyclopentylidene groupor a cyclohexylidene group, characterized in that a cyclopentanonederivative represented by the following general formula (4):

wherein R¹, R³ and R⁴ are the same as defined above, is reacted underalkaline conditions with a ketone or aldehyde represented by thefollowing general formula (5):

wherein R⁹ and R¹⁰ represents a hydrogen atom, or an alkyl group having1 to 6 carbon atoms; the alkyl groups for R⁹ and R¹⁰ may be bondedtogether to form a ring; and the total number of carbon atoms in the sumof the alkyl groups for R⁹ and R¹⁰ is in the range of 3 to
 6. 9. Aprocess for preparing a cyclopentanone derivative represented by thefollowing general formula (7):

wherein R³ and R⁴ are the same as defined above, R¹² represents an alkylgroup having 4 to 7 carbon atoms or a cyclohexyl group, and R¹³represents an alkyl group having 4 to 7 carbon atoms, a cyclopentylgroup or a cyclohexyl group, characterized in that a cyclopentanonederivative represented by the above-mentioned general formula (6) isreduced with hydrogen.
 10. A process for preparing a cyclopentanonederivative represented by the following general formula (8):

wherein R³, R⁴, R¹² and R¹³ are the same as defined above, characterizedin that a cyclopentanone derivative represented by the above-mentionedgeneral formula (7) is reduced with hydrogen.
 11. A process forpreparing a cyclopentanone derivative represented by the above-mentionedgeneral formula (a), characterized in that a cyclopentanone derivativerepresented by the following general formula (9):

wherein R³ and R⁴ are the same as defined above, R¹⁴ represents an alkylgroup having 4 to 7 carbon atoms, an alkylidene group having 4 to 7carbon atoms, a cyclohexyl group or a cyclohexylidene group, R¹⁵represents an alkyl group having 4 to 7 carbon atoms, an alkylidenegroup having 4 to 7 carbon atoms, a cyclopentyl group, acyclopentylidene group, a cyclohexyl group or a cyclohexylidene group,and at least one of R¹⁴ and R¹⁵ is the alkylidene group, acyclohexylidene group or a cyclopentylidene group, is reduced withhydrogen.